I first saw this FREE pattern months ago http://machenmachen.wordpress.com/patterns/
and fell in love. I was scouting a fabric store with bargains I could not pass up and I felt like a new bag, so I bought fabric and voila! [Note: I made the handles longer than the original pattern because I prefer cross-body.]
The piece that runs upward diagonally across (L-R) is a key leash.
My sister wanted one too. Hers is suede inside and out. It was much harder to sew (I have the bloody fingers to prove it) but it turned out okay in the end. [I used the same lining].